Some Senate Republicans said the upcoming aid package for Ukraine could draw an amendment adding sanctions on Iran, although others cautioned against that approach.

“It could be,” Republican Conference Chairman John Thune, R-S.D., said when asked if such an amendment would come up. “I am sure there will be some interest.” Thune said he had not heard of a member planning to offer an Iran sanctions amendment, but other Republicans said it could be a tempting legislative vehicle.

“Potentially,” Sen. Marco Rubio, R-Fla., said when asked about the possibility.

“The problem with Iran sanctions around here is they won’t even give us a vote on it,” Rubio continued. “We are always looking for opportunities to have a vote on that issue. That is another pressing national security concern, perhaps even more pressing than the situation in Ukraine.”

Thune and other Republicans also said to expect an amendment to expedite natural gas exports to Ukraine.

The Senate Foreign Relations Committee is currently working on an aid package for Ukraine following the incursion by the Russian military into Crimea after a popular uprising ousted Ukrainian President Viktor Yanukovych, an ally of Russian President Vladimir Putin.

The Republican-led House passed its Ukraine aid package Thursday and the Democratic-run Senate is expected to act on its proposal in the near future. The House measure would allow Ukraine to be eligible for up to $1 billion in loan guarantees under a State Department program, although it doesn't include separate International Monetary Fund lending authority sought Thursday by President Barack Obama.

“Today, House Republicans acted swiftly to provide the Administration with authority to issue loan guarantees to Ukraine,” House Majority Leader Eric Cantor, R-Va., said in a release. “Russia’s invasion of a sovereign nation is a violation of international law and its legal commitments. Our actions today demonstrate that the United States stands in support of the Ukrainian people and their government. Time is of the essence, and I urge my colleagues in the Senate to pass this bill swiftly so we can provide the President with the tools he needs to help stabilize Ukraine.”

Republicans have been pushing for vote on a pending Iran sanctions bill sponsored by Sen. Robert Menendez, D-N.J., chairman of the Foreign Relations Committee.

But Senate Majority Harry Reid, D-Nev., has been unwilling to take up the Iran measure because the White House doesn’t want any congressional action while negotiations with Iran to keep them from developing a nuclear weapon are ongoing.

Republicans sought to force a vote last month on the Iran sanctions bill in connection with a Democratic veterans bill, sponsored by Vermont independent Sen. Bernard Sanders, which would have improved health care and dental care, expand educational opportunities and helped the Department of Veterans Affairs address a disability claims backlog.

The GOP offered its own veterans bill — sponsored by Sen. Richard M. Burr, R-N.C. — that included much of the Sanders package and a provision on additional Iran sanctions.

The issue derailed the Sanders bill because Democrats, who control 55 votes in the Senate, could not win the Republican votes needed for the 60 votes required to overcome a procedural hurdle.

Some Republicans worried that if an Iran sanctions amendment were offered, the Ukraine aid package could suffer the same fate.

“As much as I am for Iran sanctions, no I don’t want to confuse the two national security crises,” said Sen. Lindsey Graham, R-S.C. “I think I am sort of the Iran sanctions guy [in the Senate]. I would say ‘no, stand down.'

“The president is upping his game in the last 24 hours,” Graham continued. “Keep it up Mr. President. The House is moving; I like the way we are pushing back.”

Graham said he wouldn’t put too much stock in a vote scheduled for March 16 for the Crimean people to decide whether to secede from Ukraine. The Crimean regional government voted to secede Thursday.

“This effort to have a vote on the fate of the Crimea in two weeks is a joke,” Graham said. “Can you imagine voting against Putin with a tank outside your door?”

Sen. Johnny Isakson, R-Ga., said he too thinks the two issues should be kept on different tracks.

“I voted for our version of the VA bill because it had the Iran sanctions in it and I think we ought to do that,” Isakson said. “Ukraine is a specific issue based on Russian provocation. We probably should address it singularly.”